trying to limit the string input

[majorursa]

Right now I am trying to limit the input of the string for this zip code evalulator. but I think I am doing
string str (5); this part wrong. can some explain what is wrong here?

#include <iostream>
#include <string>
using namespace std;
 
int main ()
{
  int zip;

  string str (5);
  cout << "please enter a zip code" << endl;
  cin >> zip;
  while (zip != 5)
  {
	  if (zip == 5){
	  cout << "valid zip code" << endl;
	  }else {
	  cout << "non valid zip code" << endl;
	  }
  }
  system("pause");
  return 0;
}

[Scorpic]

int main ()
{
  string str;
  cout << "please enter a zip code" << endl;
  cin >> str;
  if (str.size() <= 5){
  cout << "valid zip code" << endl;
  }else {
  cout << "non valid zip code" << endl;
  }
 
  return 0;
}

You're having the user input set to one int, instead of the entire zipcode,
the easiest way is to have them enter in the zipcode as a string, then check to see if its size is greater than 5.

[Fransje]

You are using a constructor that takes an integer as argument. Such a constructor doesn't exist (http://www.cplusplus.com/reference/string/string/string/).
What is the zip variable actually?
Checking the length of a string (while (zip != 5)) can be done using the size() (or length() ) function: str.size() returns the length of str (amount of characters in it, http://www.cplusplus.com/reference/string/string/size/ ).

[Drumachine]

One other problem I can see (though I could be wrong) is you have used parentheses instead of square brackets on line 9.

http://www.cplusplus.com/doc/tutorial/ntcs/

[majorursa]

ok so I would doing this work

string str (zip) ;
  

[Raezzor]

No, you would just declare the string object itself. Why are you thinking you need to include parentheses in the string declaration?

[Drumachine]

You don't need to include any string length restriction on the input of 'str' because you evaluate 'str' later in the code for its validity anyway - this is what Scorpic and Raezzor are saying. Its unnecessary to have both methods of validation (i.e. your own 'IF' statement and string input length restriction)